From 45fcad39f329506d3a18ef289792d1f8bdeb0a98 Mon Sep 17 00:00:00 2001 From: Andy Green Date: Wed, 19 Nov 2008 17:09:46 +0000 Subject: introduce-resume-dependency.patch Defines a way for drivers to defer execution of resume callbacks until one or more other driver they are dependent on has itself resumed. Signed-off-by: Andy Green --- include/linux/resume-dependency.h | 78 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 include/linux/resume-dependency.h (limited to 'include') diff --git a/include/linux/resume-dependency.h b/include/linux/resume-dependency.h new file mode 100644 index 00000000000..b13aa3e2b0e --- /dev/null +++ b/include/linux/resume-dependency.h @@ -0,0 +1,78 @@ +#ifndef __RESUME_DEPENDENCY_H__ +#define __RESUME_DEPENDENCY_H__ + +/* Resume dependency framework + * + * (C) 2008 Openmoko, Inc. + * Author: Andy Green + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; version 2.1. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + * + */ + +#include + +struct resume_dependency { + struct list_head list; + + void (*callback)(void *); /* called with context as arg */ + void * context; + int called_flag; /* set to 1 after called, use for multi dep */ +}; + +/* if you are a driver accept to have other drivers as dependencies, you need to + * instantiate a struct resume_dependency above, then initialize it by invoking + * init_resume_dependency_list() on it + */ + +#define init_resume_dependency_list(_head) \ + INIT_LIST_HEAD(&_head.list); + + +/* if your resume function depends on something else being resumed first, you + * can register the dependency by calling this in your suspend function with + * head being the list held by the thing you are dependent on, and dep being + * your struct resume_dependency + */ + +#define register_resume_dependency(_head, _dep) { \ + _dep->called_flag = 0; \ + list_add(&_dep->list, &_head->list); \ +} + +/* In the resume function that things can be dependent on, at the end you + * invoke this macro. This calls back the dependent resumes now it is safe to + * use the resumed thing they were dependent on. + */ + +#define callback_all_resume_dependencies(_head) { \ + struct list_head *_pos, *_q; \ + struct resume_dependency *_dep; \ +\ + list_for_each_safe(pos, _q, &_head.list) { \ + _dep = list_entry(_pos, struct resume_dependency, list); \ + _dep->called_flag = 1; \ + (_dep->callback)(dep->context); \ + list_del(_pos); \ + } \ +} + +/* if your resume action is dependent on multiple drivers being resumed already, + * register the same callback with each driver you are dependent on, and check + * .called_flag for all of the struct resume_dependency. When they are all 1 + * you know it is the last callback and you can resume, otherwise just return + */ + +#endif -- cgit v1.2.3